Pipe fittings for connecting lengths of pipe are well known. When coupling laminar plastic (e.g., polyethylene) pipes and multilayer pipes, it is known to use a fitting including a rotatable, externally threaded nipple to which the pipe can be attached, the nipple having a base shaped to receive a wrench. Rotation of the nipple by a wrench causes the threads on the nipple to cut into the pipe, thereby preventing removal of the pipe from the fitting.
The threaded nipple is rotatably seated inside a locking nut, having an associated gasket, for tightening the nipple to any fitting having a threaded end. However, since the nipple must be coupled to the fitting by the locking nut, this connection might leak because of a faulty seal or insufficient tightening by the user. Therefore, such fitting does not always meet customary standards for use in hidden or inaccessible locations.
There are known fittings which permit rapid coupling to a pipe by pushing the pipe onto the fitting. However, these fittings include arrangements to prevent removal of the pipe from the fitting by simply pulling on the pipe. Therefore, in order to release the fitting from the pipe or vise verse, either the pipe must be cut, which prevents reuse of the fitting, or elaborate equipment is required.
Accordingly, there is a long felt need for a fitting for easy coupling and decoupling to and from plastic or other cuttable pipes.